Bright blue light at 7000' moved East along Santa Rosa Mountain, then dropped out of sight.From approx. 2 mile distance watched extremely bright blue light near the top of Santa Rosa Mountain, elevation about 7000ft. Light was moving slowly from west to east, staying level along side the mountain. Light traveled approximately 1 mile before coming to a stop and then moving west again for about a 1/4 of a mile. Brightness of blue light did not change, nor was there any flashing navigation lights. Light then went down and then up, to the side and then down out of my line of sight into the canyon at about 4000 ft elevation. At no time did I hear engine noise which is very common for any type of aircraft near my residence, as sound echo's off mountain. I jumped in my car and sped 1/2 mile to the canyon, to see if light was a man made object. Myself and other witnesses who had come to look for the light, saw nothing. If it had been an aircraft, I would have seen it or heard it in the canyon, as I had a 5 mile visibility. As a former pilot, I have never! seen an aircraft at night that matched this description.